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1. Top results related to what is a dictionary class in java 8

   • What is a "static class" in Java?

     Top Answer

     Answered Feb 18, 2019 · 1013 votes

     Java has static nested classes but it sounds like you're looking for a top-level static class. Java has no way of making a top-level class static but you can simulate a static class like this:

     • Declare your class final - Prevents extension of the class since extending a static class makes no sense
     • Make the constructor private - Prevents instantiation by client code as it makes no sense to instantiate a static class
     • Make all the members and functions of the class static - Since the class cannot be instantiated no instance methods can be called or instance fields accessed
     • Note that the compiler will not prevent you from declaring an instance (non-static) member. The issue will only show up if you attempt to call the instance member

     Simple example per suggestions from above:

     public class TestMyStaticClass { public static void main(String []args){ MyStaticClass.setMyStaticMember(5); System.out.println("Static value: " + MyStaticClass.getMyStaticMember()); System.out.println("Value squared: " + MyStaticClass.squareMyStaticMember()); // MyStaticClass x = new MyStaticClass(); // results in compile time error }}-// A top-level Java class mimicking static class behaviorpublic final class MyStaticClass { private MyStaticClass () { // private constructor myStaticMember = 1; } private static int myStaticMember; public static void setMyStaticMember(int val) { myStaticMember = val; } public static int getMyStaticMember() { return myStaticMember; } public static int squareMyStaticMember() { return myStaticMember * myStaticMember; }}-

     What good are static classes? A good use of a static class is in defining one-off, utility and/or library classes where instantiation would not make sense. A great example is the Math class that contains some mathematical constants such as PI and E and simply provides mathematical calculations. Requiring instantiation in such a case would be unnecessary and confusing. See the Math

     class and source code. Notice that it is final and all of its members are static. If Java allowed top-level classes to be declared static then the Math class would indeed be static.

     Other Answers

     Answered Sep 20, 2011 · 359 votes

     Well, Java has "static nested classes", but they're not at all the same as C#'s static classes, if that's where you were coming from. A static nested class is just one which doesn't implicitly have a reference to an instance of the outer class.

     Static nested classes can have instance methods and static methods.

     There's no such thing as a top-level static class in Java.

     Other Answers

     Answered Oct 14, 2016 · 187 votes

     There is a static nested class, this [static nested] class does not need an instance of the enclosing class in order to be instantiated itself.

     These classes [static nested ones] can access only the static members of the enclosing class [since it does not have any reference to instances of the enclosing class...]

     code sample:

     public class Test { class A { } static class B { } public static void main(String[] args) { /*will fail - compilation error, you need an instance of Test to instantiate A*/ A a = new A(); /*will compile successfully, not instance of Test is needed to instantiate B */ B b = new B(); }}-

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     1/5

   • What is a "static class" in Java?

     Top Answer

     Answered Feb 18, 2019 · 1022 votes

     Java has static nested classes but it sounds like you're looking for a top-level static class. Java has no way of making a top-level class static but you can simulate a static class like this:

     • Declare your class final - Prevents extension of the class since extending a static class makes no sense
     • Make the constructor private - Prevents instantiation by client code as it makes no sense to instantiate a static class
     • Make all the members and functions of the class static - Since the class cannot be instantiated no instance methods can be called or instance fields accessed
     • Note that the compiler will not prevent you from declaring an instance (non-static) member. The issue will only show up if you attempt to call the instance member

     Simple example per suggestions from above:

     public class TestMyStaticClass { public static void main(String []args){ MyStaticClass.setMyStaticMember(5); System.out.println("Static value: " + MyStaticClass.getMyStaticMember()); System.out.println("Value squared: " + MyStaticClass.squareMyStaticMember()); // MyStaticClass x = new MyStaticClass(); // results in compile time error }}-// A top-level Java class mimicking static class behaviorpublic final class MyStaticClass { private MyStaticClass () { // private constructor myStaticMember = 1; } private static int myStaticMember; public static void setMyStaticMember(int val) { myStaticMember = val; } public static int getMyStaticMember() { return myStaticMember; } public static int squareMyStaticMember() { return myStaticMember * myStaticMember; }}-

     What good are static classes? A good use of a static class is in defining one-off, utility and/or library classes where instantiation would not make sense. A great example is the Math class that contains some mathematical constants such as PI and E and simply provides mathematical calculations. Requiring instantiation in such a case would be unnecessary and confusing. See the Math

     class and source code. Notice that it is final and all of its members are static. If Java allowed top-level classes to be declared static then the Math class would indeed be static.

     Other Answers

     Answered Sep 20, 2011 · 359 votes

     Well, Java has "static nested classes", but they're not at all the same as C#'s static classes, if that's where you were coming from. A static nested class is just one which doesn't implicitly have a reference to an instance of the outer class.

     Static nested classes can have instance methods and static methods.

     There's no such thing as a top-level static class in Java.

     Other Answers

     Answered Oct 14, 2016 · 187 votes

     There is a static nested class, this [static nested] class does not need an instance of the enclosing class in order to be instantiated itself.

     These classes [static nested ones] can access only the static members of the enclosing class [since it does not have any reference to instances of the enclosing class...]

     code sample:

     public class Test { class A { } static class B { } public static void main(String[] args) { /*will fail - compilation error, you need an instance of Test to instantiate A*/ A a = new A(); /*will compile successfully, not instance of Test is needed to instantiate B */ B b = new B(); }}-

     Check all answers on Stack Overflow

     2/5

   • What is a "runtime class" in Java?

     Top Answer

     Answered Nov 08, 2016 · 8 votes

     Just understand it as "an object that has all the metadata of the object's type". In that object, you can find the methods declared in the class, the fields, the type hierarchy, etc. This information will be typically used by code that uses reflection to either inspect objects/types or to run method without the need to have the class defined and compiled when they, themselves are being coded.

     "Runtime" may be emphasized because the class definition may change over time, or the object may be declared as a supertype while it actually is an instance of a subtype of the one declared. When a certain class is loaded, it's that information, as loaded during that instance, that will be returned by the getClass() method.

     In short, when your code runs, the VM will have a definition of your class in a different way than the "source" form that you type in a .java file. That information, of course after being compiled, will be loaded and all the metadata (as said above) will constitute what they call the "runtime class". It's just a fancy way to say "an object with all the metadata about a class loaded when the program is running"

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     3/5

   • What is a peer class in Java?

     Top Answer

     Answered Mar 03, 2015 · 15 votes

     First of all: You have to be careful with the term "peer class", because in Java it has a distinct meaning: Peer classes are "interfaces" to native classes. (a C++ class for example) (See the other anwsers for details)

     In your case the term seems not to be used in that specific context!

     Whoever called StringBuffer a peer class to String obviously used that word in a general sense. In a way StringBuffer and String are related and both of them can be used for similar purposes. I guess in some use cases they could be considered peers in the broader sense of the word.

     Check all answers on Stack Overflow

     4/5

   • What is a Class Library in Java?

     Top Answer

     Answered Jul 25, 2009 · 8 votes

     It's a collection of classes, usually bundled up in a jar file. All the classes may be in the same Java package, but they don't have to be. A class library in a jar file may also contain resources and meta-data that it needs (e.g. string translations, driver information for other frameworks etc).

     Check all answers on Stack Overflow

     5/5

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2. www.geeksforgeeks.org › java-util-dictionary-classJava.util.Dictionary Class in Java - GeeksforGeeks

   www.geeksforgeeks.org › java-util-dictionary-class

   • Cached

   Apr 9, 2023 · The java.util.Dictionary class is a class in Java that provides a key-value data structure, similar to the Map interface. It was part of the original Java Collections framework and was introduced in Java 1.0. However, the Dictionary class has since been considered obsolete and its use is generally discouraged.

3. docs.oracle.com › api › javaDictionary (Java Platform SE 8 ) - Oracle

   docs.oracle.com › api › java

   • Cached

   The Dictionary class is the abstract parent of any class, such as Hashtable, which maps keys to values. Every key and every value is an object. In any one Dictionary object, every key is associated with at most one value. Given a Dictionary and a key, the associated element can be looked up.

4. People also ask

   What is a dictionary in Java?

   • Dictionary () Sole constructor. The java.util.Dictionary class is a class in Java that provides a key-value data structure, similar to the Map interface. It was part of the original Java Collections framework and was introduced in Java 1.0. However, the Dictionary class has since been considered obsolete and its use is generally discouraged.

   Java.util.Dictionary Class in Java - GeeksforGeeks

   www.geeksforgeeks.org/java-util-dictionary-class-java/

   See all results for this question

   What happened to the Java Dictionary class?

   • The Java Dictionary class has now become obsolete and currently all the collection types that store data in the form of key-value pairs implement the Java Map interface. However, the Java Dictionary class variables can still be used to store a reference to the Hashtable classes implementing the Map interface.

   Understanding the Java Dictionary Class - Udemy Blog

   blog.udemy.com/java-dictionary/

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   What is a dictionary class?

   • The Dictionary class is the abstract parent of any class, such as Hashtable, which maps keys to values. Every key and every value is an object. In any one Dictionary object, every key is associated with at most one value. Given a Dictionary and a key, the associated element can be looked up.

   Dictionary (Java Platform SE 8 ) - docs.oracle.com

   docs.oracle.com/javase/8/docs//api/java/util/Dictionary.html

   See all results for this question

   What is the difference between dictionary and map in Java?

   • Dictionary is an abstract class whereas Map is an interface, hence it is more Java-idiomatic. Dictionary was deprecated early in Java 1.2 and replaced by its better interface counterpart, Map. This leads to believed that Dictionary was just a bad design choice and the Java folks kept the Dictionary class for backward compatibility.

   What is the difference between the Dictionary class and the Map class

   stackoverflow.com/questions/25900226/what-is-the-difference-between-the-dictionary-class-and-the-map-class-in-java

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5. www.toolsqa.com › java › dictionary-classDictionary Class in Java | Dictionary usage in Java - Tools QA

   www.toolsqa.com › java › dictionary-class

   • Cached

   Jul 27, 2021 · The Dictionary class. In Java, a Dictionary is an abstract class that maps keys to values. Both keys and values can be objects of any type but not null. An attempt to insert either a null key or a null value to a dictionary causes a NullPointerException exception. Therefore, it’s mandatory to provide a non-null value for both keys and values.

6. stackoverflow.com › questions › 13543457How do you create a dictionary in Java? - Stack Overflow

   stackoverflow.com › questions › 13543457

   • Cached

   This creates dictionary of text (string): Map<String, String> dictionary = new HashMap<String, String>(); you then use it as a: dictionary.put("key", "value"); String value = dictionary.get("key"); Works but gives an error you need to keep the constructor class same as the declaration class.

   Code sample

   Map<String, String> map = new HashMap<String, String>();

   map.put("dog", "type of animal");

   System.out.println(map.get("dog"));

   See more on stackoverflow

7. www.learnsic.com › blog › understanding-the-javaUnderstanding the Java Dictionary Class - learnsic.com

   www.learnsic.com › blog › understanding-the-java

   • Cached

   Mar 28, 2024 · Posted By: Khim Panthi. In Java, the Dictionary class is an abstract class representing a data structure for storing key-value pairs. It is the root interface for hash table-based implementations, such as Hashtable and Properties.

8. javatothepoint.com › dictionary-class-in-javaDictionary Class in Java - Java To The Point

   javatothepoint.com › dictionary-class-in-java

   • Cached

   May 10, 2023 · The Dictionary class is an abstract class that defines a data structure for managing key-value pairs. It is the superclass of the Hashtable and Properties classes. The Dictionary class is a legacy class, which means it was introduced in an earlier version of Java and has been replaced by newer classes.

9. www.tutorialspoint.com › java_data_structures › javaJava Data Structures - Dictionary class

   www.tutorialspoint.com › java_data_structures › java

   • Cached

   Dictionary is an abstract class that represents a key/value storage repository and operates much like Map. Given a key and value, you can store the value in a Dictionary object. Once the value is stored, you can retrieve it by using its key. Thus, like a map, a dictionary can be thought of as a list of key/value pairs.